The 800 series has a number of modifications and changes over the 700; most noticeable was the redesigned cockpit windscreen. Accompanying this are a modified rear fuselage fairing as well as a glass cockpit and uprated (from 3,700 to 4,300 lb) Garrett TFE731-5R-1H engines. British Aerospace also improved the wing by incorporating new outer wing sections. This helped to reduce drag and improve aerodynamic efficiency.
The 800 series would become a sales success. From the first BAe 125 flight in August 1961 it took nineteen years until the 500th airframe was sold. In a little over five years British Aerospace were registering the 200th sale of the 800 series.
In 1994 Beech Aircraft (which was also controlled by Raytheon) merged with Raytheon Corporate Jets to form Raytheon Aircraft. In March 2007, Raytheon Aircraft Company was sold to Hawker Beechcraft Corp., a company formed and controlled by GS Capital Partners (an affiliate of Goldman Sachs) and Onex Partners of Canada.
The current version is identified as the Hawker 850XP and was certified for operation in March 2006. The 850XP is identical to the 800XP except that it includes winglets which have extended its operating range by 100 nautical miles. This version also incorporates upgraded avionics and a redesigned interior. The Hawker 850XP essentially fills the gap left behind by the Hawker 1000 when production of that aircraft ceased.
Two new variants were announced in October 2006 for future deliveries:
A military version of the Hawker 800 is in use by South Korea for tactical reconnaissance, surveillance and SIGINT (SIGnals INTelligence) tasks, and 8 specially-equipped aircraft were delivered in 2000. The Republic of Korea Air Force calls them RC-800s, and they are based at Seongnam.
Japan uses a maritime search and rescue variant of the Hawker 800. It is designated U-125A in Japan Air Self-Defense Force service. This variant has large observation windows, a flare and marker-buoy dispenser system, life-raft and emergency equipment dropping system and enhanced salt water corrosion prevention. The aircraft also has a Toshiba 360-degree search radar, melco thermal imaging equipment and other military communications equipment for its mission.